The skin is the organ that covers the outside of the body and consists of three layers. From the outside in, they are the epidermis, the dermis and the subcutaneous layer. The epidermis is mainly composed of keratinocytes of stratified squamous epithelium. The dermis, composed of matrix proteins such as collagen fibers and elastic fibers, is located beneath the epidermis. The dermis contains blood vessels, nerves, sweat glands, etc. The subcutaneous layer is composed of adipocytes. These various cells and constituent materials interact with each other to maintain the skin shape and allow the skin to perform various functions such as thermoregulation, a barrier to external environments, etc.
Artificial skin is produced by three-dimensionally constructing a skin equivalent using skin cells and collagen, elastin, etc. which constitute the skin. It consists of living fibroblasts and keratinocytes and has similar constructional and functional properties to the real skin. Thus, it is also called a skin equivalent or a reconstructed skin. Artificial skin is a polymer complex that has similar properties to the skin mainly in elasticity, strength, and material permeability, etc. It differs from the skin in that it does not involve life phenomena as in the skin. Artificial skin is used not only for replacing (permanent engraftment type) or regenerating (temporary coating type) the skin damaged due to a burn or a wound, etc. but also in various fields such as skin physiology research, skin irritation evaluation, evaluation of effects on the skin.
However, existing artificial skins are produced by mixing collagen and dermis fibroblasts, solidifying them to obtain a dermal layer and then culturing it. During the tissue culture, collagen and fibroblast interact with each other, which inevitably leads to gradual contraction of the dermis. As a result, the dermal layer of the artificial skin is detached from the culture container during the production of the artificial skin. Furthermore, when the dermis contraction is severe, the structure of the artificial skin tissue is totally deformed and the tissue becomes physiologically abnormal, and accordingly the artificial skin has to be discarded.